Disclosed herein are hot melt or phase change inks containing bis(urea-urethane) compounds. One embodiment is directed to a phase change ink composition comprising a phase change ink carrier and a bis(urea-urethane) compound of the formula
wherein R1 and R1′ each, independently of the other, is an alkyl group, an aryl group, an arylalkyl group, or an alkylaryl group, R2 and R2′ each, independently of the other, is an alkylene group, an arylene group, an arylalkylene group, or an alkylarylene group, R3 is an alkylene group, an arylene group, an arylalkylene group, or an alkylarylene group, and R4 and R5 each, independently of the other, is a hydrogen atom or an alkyl group.
In general, phase change inks (sometimes referred to as “hot melt inks”) are in the solid phase at ambient temperature, but exist in the liquid phase at the elevated operating temperature of an ink jet printing device. At the jet operating temperature, droplets of liquid ink are ejected from the printing device and, when the ink droplets contact the surface of the recording substrate, either directly or via an intermediate heated transfer belt or drum, they quickly solidify to form a predetermined pattern of solidified ink drops. Phase change inks have also been used in other printing technologies, such as gravure printing, as disclosed in, for example, U.S. Pat. No. 5,496,879 and German Patent Publications DE 4205636AL and DE 4205713AL, the disclosures of each of which are totally incorporated herein by reference.
Phase change inks for color printing typically comprise a phase change ink carrier composition which is combined with a phase change ink compatible colorant. In a specific embodiment, a series of colored phase change inks can be formed by combining ink carrier compositions with compatible subtractive primary colorants. The subtractive primary colored phase change inks can comprise four component dyes, namely, cyan, magenta, yellow and black, although the inks are not limited to these four colors. These subtractive primary colored inks can be formed by using a single dye or a mixture of dyes. For example, magenta can be obtained by using a mixture of Solvent Red Dyes or a composite black can be obtained by mixing several dyes. U.S. Pat. Nos. 4,889,560, 4,889,761, and 5,372,852, the disclosures of each of which are totally incorporated herein by reference, teach that the subtractive primary colorants employed can comprise dyes from the classes of Color Index (C.I.) Solvent Dyes, Disperse Dyes, modified Acid and Direct Dyes, and Basic Dyes. The colorants can also include pigments, as disclosed in, for example, U.S. Pat. No. 5,221,335, the disclosure of which is totally incorporated herein by reference. U.S. Pat. No. 5,621,022, the disclosure of which is totally incorporated herein by reference, discloses the use of a specific class of polymeric dyes in phase change ink compositions.
Phase change inks have also been used for applications such as postal marking, industrial marking, and labelling.
Phase change inks are desirable for ink jet printers because they remain in a solid phase at room temperature during shipping, long term storage, and the like. In addition, the problems associated with nozzle clogging as a result of ink evaporation with liquid ink jet inks are largely eliminated, thereby improving the reliability of the ink jet printing. Further, in phase change ink jet printers wherein the ink droplets are applied directly onto the final recording substrate (for example, paper, transparency material, and the like), the droplets solidify immediately upon contact with the substrate, so that migration of ink along the printing medium is prevented and dot quality is improved.
Compositions suitable for use as phase change ink carrier compositions are known. Some representative examples of references disclosing such materials include U.S. Pat. Nos. 3,653,932, 4,390,369, 4,484,948, 4,684,956, 4,851,045, 4,889,560, 5,372,852, 5,496,879, European Patent Publication 0187352, European Patent Publication 0206286, German Patent Publication DE 4205636AL, German Patent Publication DE 4205713AL, and PCT Patent Application WO 94/04619, the disclosures of each of which are totally incorporated herein by reference. Suitable carrier materials can include paraffins, microcrystalline waxes, polyethylene waxes, ester waxes, fatty acids and other waxy materials, fatty amide containing materials, sulfonamide materials, resinous materials made from different natural sources (tall oil rosins and rosin esters, for example), and many synthetic resins, oligomers, polymers, and copolymers.
U.S. Pat. No. 6,761,758 (Boils-Boissier et al.), the disclosure of which is totally incorporated herein by reference, discloses compounds of the formulae
wherein, provided that at least one of R1, R2, R3, R4, R5, and R6 is a hydrogen atom, and provided that at least one of R1, R2, R3, R4, R5, and R6 is not a hydrogen atom, R1, R2, R3, R4, R5, and R6 each, independently of the others, is (i) a hydrogen atom, (ii) an alkyl group, (iii) an aryl group, (iv) an arylalkyl group, or (v) an alkylaryl group. Also disclosed are phase change ink compositions comprising a colorant and a phase change ink carrier comprising a material of this formula.
U.S. Pat. No. 6,471,758 and European Patent Publication EP 1 067 157 (Kelderman et al.), the disclosures of each of which are totally incorporated herein by reference, disclose an ink composition for a meltable ink usable in a printing device in which ink drops are ejected from ink ducts, which comprises agents which reversibly cross-link the ink, the said agents containing a gelling agent. When an ink drop which has been transferred to a substrate passes over into a gel during the cooling process, the consequence is that the viscosity of the melted ink drop increases greatly so that the drops become relatively immobile. In this way the ink drops are prevented from uncontrollably flowing into the paper. As a result, inks of this kind are suitable for use on both porous and smooth substrates. In addition, these inks have been found suitable for use in a printing device in which printed substrates are subjected to thermal after-treatment.
“Cyclic Bis-Urea Compounds as Gelators for Organic Solvents,” J. van Esch et al., Chem. Eur. J. 1999, 5, No. 3, pp. 937–950, the disclosure of which is totally incorporated herein by reference, discloses the study of the gelation properties of bis-urea compounds derived from optically pure trans-1,2-diaminocyclohexane and 1,2-diaminobenzene, with pendant aliphatic, aromatic, or ester groups, as well as the structure of the resulting gels.
“The Design of Organic Gelators Based on a Family of Bis-Ureas,” R. E. Meléndez et al., Mat. Res. Soc. Symp. Proc. 2000, 604, pp. 335–340, the disclosure of which is totally incorporated herein by reference, discloses a study of the organogelation properties of a family of bis-ureas.
“Formation of Organogels by Intermolecular Hydrogen Bonding Between Ureylene Segment,” K. Hanabusa et al., Chem. Lett. 1996 pp. 885–886, the disclosure of which is totally incorporated herein by reference, discloses low molecular weight compounds having ureylene segment causing physical gelation in organic solvents. The main driving force for gelation was intermolecular hydrogen bonding between ureylene units.
“Low Molecular Weight Gelators for Organic Solvents,” J. van Esch et al., in Supramolecular Science: Where Is It and Where It Is Going, R. Ungaro and E. Dalcanale, Eds., 1999, Netherlands: Kluwer Academic Publishers, pp. 233–259, the disclosure of which is totally incorporated herein by reference, discloses the gelation of solvents by organogelators.
“Organogels and Low Molecular Mass Organic Gelators,” D. J. Abdallah and R. G. Weiss, Adv. Mater. 2000, 12, No. 17, September 1, pp. 1237–1247, the disclosure of which is totally incorporated herein by reference, discloses the stepwise simplification of low molecular-mass organic gelator structures and the development of methods to determine their packing in organogels at the micrometer-to-angstrom distance regimes, as well as an overview of current and potential applications for these materials.
“Remarkable Stabilization of Self-Assembled Organogels by Polymerization,” M. de Loos et al., J. Am. Chem. Soc. 1997, 119, 12675–12676, the disclosure of which is totally incorporated herein by reference, discloses studies of polymerizable bis(amido)cyclohexane and bis(ureido)cyclohexane derivatives, investigating their gelating capacity for organic solvents.
“Low-molecular weight organogelators,” P. Terech, in Specialist Surfactants, I. D. Robb, Ed., 1997, London: Chapman & Hall, pp. 208–68, the disclosure of which is totally incorporated herein by reference, discloses a special class of surfactants which have the ability to form viscoelastic fluids or solid-like materials in organic solvents at concentrations lower than about 2 percent.
“New Functional Materials Based on Self-Assembling Organogels: From Serendipity Towards Design,” J. H. van Esch and B. L. Feringa, Angew. Chem. Int. Ed. 2000, 39, No. 13, pp. 2263–2266, the disclosure of which is totally incorporated herein by reference, discloses a review of developments in the field of organogels.
“Synthesis and Self-Assembling Properties of Polymerizable Organogelators,” G. Wang and A. D. Hamilton, Chem. Eur. J. 2002, 8, No. 8, pp. 1954–1961, the disclosure of which is totally incorporated herein by reference, discloses the development of a family of polymerizable urea derivatives that are gelators for organic solvents.
“Low Molecular Mass Gelators of Organic Liquids and the Properties of their Gels,” P. Terech and R. G. Weiss, Chem. Rev. 1997, 97, pp. 3133–3159, the disclosure of which is totally incorporated herein by reference, discloses a review of the properties of thermally-reversible viscoelastic liquidlike or solidlike organogels comprising an organic liquid and low concentrations of relatively low molecular mass gelator molecules.
“Towards a Phenomenological Definition of the Term ‘Gel’,” K. Amdal et al., Polymer Gels and Networks, 1993, 1, pp. 5–17, the disclosure of which is totally incorporated herein by reference, discusses existing definitions of the term “gel” and proposes specific uses of the term.
PCT Patent Publication WO 03/084508 and European Patent Publication EP 1 350 507 (Friesen et al.), the disclosures of each of which are totally incorporated herein by reference, disclose delivery vehicles for delivering a substance of interest to a predetermined site, said vehicle comprising said substance and a means for inducing availability of at least one compartment of said vehicle toward the exterior, thereby allowing access of said substance to the exterior of said vehicle at said predetermined site. The invention is further concerned with uses of said vehicle and methods for preparing it.
PTC Patent Publication WO 03/040135 (Dowle et al.), the disclosure of which is totally incorporated herein by reference, discloses compounds of the formula
in which R is an amino or guanidino group, R2 is acetyl or trifluoroacetyl, X is CONH, SO2NH, NHCO, or NHCONH, m is either 0 or 1, n is an integer from 2 to 6, q is an integer from 0 to 3, and Y is hydrogen or an aromatic substituent, or a pharmaceutically acceptable derivative thereof. Also disclosed are methods for their preparation, pharmaceutical formulations containing them, and their use in the prevention or treatment of a viral infection.
PTC Patent Publication WO 00/55149 and U.S. Pat. No. 6,548,476 (Wu et al.), the disclosures of each of which are totally incorporated herein by reference, disclose dimeric compounds, methods for their preparation, pharmaceutical formulations thereof, and their use as antiviral agents. The compounds are particularly useful against influenza virus. In particular the references disclose a dimeric compound which comprises two neuraminidase binding groups attached to a spacer or linking group. Preferably the dimeric molecule comprises two neuraminidase-binding neuraminic acid (sialic acid) or cyclopentyl or cyclohexenyl carboxylic acid derivatives covalently attached to a common spacer group. Pharmaceutical compositions and methods of treatment, prophylaxis and diagnosis are disclosed and claimed.
U.S. Patent Publication 20010044553 (Kabashima et al.), the disclosure of which is totally incorporated herein by reference, discloses a urea-urethane compound having one or more urea groups and one or more urethane groups in the molecular structure, the number of said urea groups (A) and the number of said urethane groups (B) satisfying the following numerical formula: 10≧(A+B)≧3 wherein each of A and B is an integer of 1 or more.
European Patent Publication EP 1 048 681 and U.S. Pat. No. 6,420,466 (Haubennestel et al.), the disclosures of each of which are totally incorporated herein by reference, disclose a process for preparing a solution that is active as a thixotropic agent and contains urea urethanes, in which monohydroxyl compounds are reacted with an excess of toluene diisocyanate, the unreacted portion of the toluene diisocyanate is removed from the reaction mixture, and the monosiocyanate adduct obtained is further reacted with diarines in the presence of a lithium salt to form urea urethanes. The invention also relates to the use of the solution for imparting thixotropic properties to coating compounds.
Japanese Patent Publication JP 10310633, the disclosure of which is totally incorporated herein by reference, discloses a cationic curing catalyst composition improved in stability during storage at room temperature or above and suppressed in increase in viscosity, using at least one stabilizer selected from the compounds containing a urethane bond, an amide bond, a urea bond and a carbodiimide group in the molecule and a dialkylaminopyridine compound or a proton acid compound.
European Patent Publication EP 0 056 153 and U.S. Pat. No. 4,384,102 (Rasshofer et al.), the disclosures of each of which are totally incorporated herein by reference, disclose compounds having both s-triazine units and epoxide groups present that are prepared by reacting an epoxide containing an isocyanate-reactive group with a triisocyanate corresponding to the formula
in which X is as defined therein. These reactants are used in quantities such that the equivalent ratio of isocyanate groups to isocyanate-reactive groups is maintained at less than or equal to 1 to 1. The compounds thus produced are particularly useful as reactive cross-linkers in the production of polyurethanes and polyepoxides.
European Patent Publication EP0 160402 and U.S. Pat. No. 4,566,981 (Howells), the disclosures of each of which are totally incorporated herein by reference, disclose cationic and non-ionic fluorochemicals, mixtures of cationic and non-ionic fluorochemicals, blends of the mixtures with fluorochemical poly(oxyalkylenes), and compositions of the fluorochemicals with hydrocarbon nonionic surfactants. These fluorochemicals and compositions, in dispersions, emulsions and microemulsions, may be applied to porous fibrous substrates to give oil and water repellency and soil resistance.
Japanese Patent Publication JP 59030919, the disclosure of which is totally incorporated herein by reference, discloses a method to prevent the bad influence of a treatment on spinning properties and drawing properties of synthetic yarn, by providing undrawn yarn of melt spinning with a spinning oil, applying a specific treatment to it, drawing and heat-treating it. The undrawn yarn which is prepared by melt spinning and cooled is provided with a spinning oil by the oil applicator, coated with a treatment by the treatment applicator, sent through the taking up roller and the drawing rollers, and wound around the winder. The treatment is a compound shown by the formula (Rf-A-B1—CONH—X—NHCO—B2-)nY (Rf is 4–16C perfluoroalkyl; A is —(CH2)x1—, CON(R1)—(CH2)x2—, or SO2N(R1)—(CH2)x2—; x1 is 1–20 integer; x2 is 1–12 integer; R1 is H, or 1–6C alkyl; B1 and B2 are —O—, —S—, or —N(R2)—; R2 is H, or 1–4C alkyl; X is bifunctional organic group; Y is polyfunctional organic group; n is 2–10 integer) and its pickup is 0.03–2.0 wt %.
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Known organogelator compounds containing two or more urea functional groups exhibit some disadvantages for performing in a phase-change solid ink vehicle, such as high melting point and high degree of crystallinity.
Many currently used phase change inks require high jetting temperatures of about 140° C. or greater and also require relatively long warmup times for the printer. In addition, many currently used phase change inks generate images with relatively poor scratch resistance and relatively poor image permanence.
While known compositions and processes are suitable for their intended purposes, a need remains for improved phase change ink compositions. In addition, a need remains for phase change inks that can be jetted at reduced temperatures of about 110° C. or lower, thereby enabling cost and energy savings. Further, a need remains for phase change inks that enable printing with reduced printer warm-up times. Additionally, a need remains for phase change inks that generate images with improved scratch resistance. There is also a need for phase change inks that generate images with improved image permanence. In addition, there is a need for phase change inks that generate images with improved image quality. Further, there is a need for phase change inks that exhibit the aforementioned advantages when used in a printing process wherein the ink is first jetted onto an intermediate transfer member and subsequently transferred from the intermediate transfer member to a final print substrate such as plain or coated paper or a transparency. Additionally, there is a need for phase change inks that exhibit the aforementioned advantages when used in a printing process wherein the ink is jetted directly onto a final print substrate such as plain or coated paper or a transparency. A need also remains for phase change inks that exhibit the aforementioned advantages when used in printing processes at relatively high speeds. In addition, a need remains for phase change inks having desirably low melting points that also contain gelator compounds which enable additional advantages in the phase change inks. Further, a need remains for gelator compounds for use in phase change inks and other applications that have a desirably low degree of crystallinity. Additionally, a need remains for gelator compounds that are soluble in phase change ink carriers. There is also a need for phase change inks that exhibit an intermediate gel phase between the solid phase and the liquid phase. In addition, there is a need for phase change inks exhibiting an intermediate gel phase wherein the gel phase transition is desirably narrow. Further, there is a need for gelator compounds that enable desirably narrow gel phase transitions. Additionally, there is a need for phase change inks exhibiting an intermediate gel phase wherein the gel phase transition entails a tan-delta of less than about 10. A need also remains for gelator compounds that enable gel phase transitions entailing a tan-delta of less than about 10. In addition, a need remains for gelator compounds that are less highly crystalline and do not pack as tightly within a molecular network as do more crystalline materials, thereby enabling them to be soluble within molten phase change inks.